1. Field of the Invention
The present invention relates to processes for preparing phenoxypyridine derivatives (hereafter referred to as “the present compound”) useful as an anti-tumor agent and an inhibitor for cancer metastasis having inhibitory activity against hepatocyte growth factor receptor (hereafter referred to as “HGFR”), anti-tumor activity, inhibitory activity against angiogenesis, inhibitory activity against cancer metastasis or the like, and to preparation intermediates in the processes.
2. Related Background Art
Overexpression of HGFR is reported in various kinds of tumors such as a pancreatic cancer, a gastric cancer, a colorectal cancer, a breast cancer, a prostate cancer, a lung cancer, a renal cancer, a brain tumor or an ovarian cancer (non-patent document 1). HGFR expressed in these cancer cells is considered to be involved in cancer malignancy (aberrant growth, invasion or enhanced metastasis), because HGFR cause autophosphorylation of intracellular tyrosine kinase constitutively or upon stimulation by hepatocyte growth factor (hereafter referred to as “HGF”).
It is also reported that HGFR is expressed in vascular endothelial cells and is involved in tumor angiogenesis since HGF stimulates HGFR to facilitate proliferation and migration of vascular endothelial cells (non-patent document 2).
Furthermore, NK4, an antagonistic peptide for HGF, is reported to block HGF-HGFR signal to inhibit invasion of cancer cells and tumor angiogenesis (non-patent documents 3 and 4).
Therefore, a compound having inhibitory activity against HGFR is expected to be useful as an anti-tumor agent, an angiogenesis inhibitor or an inhibitor for cancer metastasis.
By the way, patent document 1 discloses compounds similar to the present compounds in structure and processes for preparing the same, but does not disclose the processes for preparing the present compounds according to the present invention and the preparation intermediates in the processes as well as the present compounds.
[Patent document 1] WO 2005/082855
[Non-patent document 1] Oncology Reports, 5, 1013-1024 (1998)
[Non-patent document 2] Advances in Cancer Research, 67, 257-279 (1995)
[Non-patent document 3] British Journal of Cancer, 84, 864-873 (2001)
[Non-patent document 4] Cancer Sci., 94, 321-327 (2003)